Ocampa

The Ocampa are a species of humanoidsapients native to the Delta Quadrant. They are notable for having abnormally short lifespans, telepathic abilities, and -- despite reproducing sexually -- giving birth only once in their lifetime. There are two known populations of this species, the largest of which is in all likelihood extinct by now.

The Ocampa are perhaps the most unfit-to-live species ever devised in Star Trek.

They have a life expectancy of less than 20 years (at best, most live less than 10 years).

They only mate to produce children once in their lives.

A typical mating only produces one child.

By this idiotic math, each Ocampa generation is no more than half the size of the previous one, which means they're rushing toward extinction at ludicrous speed. In reality, nature would never produce a species with such absurd reproductive characteristics. The only way it could possibly work on the long term involves invoking a Mr. Seahorse, so both genders can produce a viable offspring. Even that would only maintain a steady population under ideal conditions; any Ocampa who died before reproducing would reduce the population.

The stupidity is such that it lead to Chuck proposing that the Ocampa are actually a genetically engineered race specifically created to be sex slaves. Nearly everything about them fits into this somewhat disturbing scenario. They reach maturity quickly and stay young looking for most of their lives up until right before their deaths.

Psychic Ability

All Ocampa are capable of communicating telepathically with other members of their race. With training, Ocampa can expand their mental powers to include telepathic contact with other races and telekinetic abilities.